This invention relates to hardware initialization, and more particularly to enabling an extended hardware initialization.
The operation of an Application Specific Integrated Circuit (ASIC) may be controlled by data stored in control registers in the ASIC. When the ASIC is powered on, a reset signal may be transmitted to the ASIC. This reset signal may trigger a register initialization in which the contents of the control registers may be set to default values. Upon completion of the register initialization, the ASIC may enter an operating mode.
The default values in the control registers may not be appropriate for one or more operations the ASIC may perform in the operating mode. A processor may perform read and write operations to the control registers to configure the control registers for the operating mode. Depending on the number of control registers, the configuration may take several seconds. However, the processor may not have read or write access to the control registers during the register initialization. When the ASIC enters the operating mode, certain control registers may still contain default values that may not be appropriate for the operation the ASIC is performing. Thus, the ASIC may begin operating before it is appropriately configured for the operating mode. This may result in a xe2x80x9cgrayxe2x80x9d operating period in which the performance of the ASIC may be unpredictable.
According to an embodiment, an initialization extension device may provide an extended initialization period to enable a processor to configure a device, for example, an application specific integrated circuit (ASIC), prior to entering an operating mode. The device may include a number of control registers that may be configured to default settings in a register initialization period commenced in response to a reset signal. The reset signal may also trigger an extension timer to countdown a timer extended initialization period. During the timer extended initialization period, the processor may write an extension control signal, e.g., an extension bit, to a register. An initialization extension unit may maintain the device in an initialization mode during the timer extended initialization period and/or while the register contains the extension control signal. The processor may configure the control registers for one or more operations the device may perform when it enters the operating mode.
The details of one or more embodiments are set forth in the accompanying drawings and the description below. Other features, objects, and advantages of various embodiments will be apparent from the description and drawings, and from the claims.